Improvement in grinding-mills



J. A. PORSMAN] .Flolir Mill.

No. 107,353. Patent-ed Sept, 13,1870.

MPETERS, PNOTO-LITHOGRIPHER, WASHINGTON, I?!v G.

UNITED STATES PATENT OFFICE.

JOSEPH A. FORSMAN', OF CHICAGO, ILLINOIS.

IMPROVEMENT IN GRINDING-MILLS.

Specification forming part of Letters PatentNo. 107,353, dated September13, 1870.

To all whom it may concern.- Be it known that I, JOSEPH A. FORSMAN, ofChicago, in the county of Cook and State of Illinois, have invented anew and useful Improvement in Grinding-Mills; and I do declare that thefollowing is a true and accurate description thereof, reference beinghad to the accompanying drawings, and to the letters of reference markedthereon, and being apart of this specification, of which Figure 1 is asectional perspective of the runner-stone from the rear side, showingthe improved method of securing the back plate and spindle thereto. Fig.2 is a perspective of the face side of the stationary stone, showing myimproved method of securing the same in the case. Fig. 3 is an axialsection of the last figure.

Like letters indicatelike parts in each figure. The nature of thisinvention relates to an improvement in the construction ofgrindingmills; and it consists, first, in an improved method of securingthe back plate, spindle, and driving-pulley to the runner-stone,wherebythe same are more effectually secured in place and the bursting of thestone prevented from the causes inherent in such mills as heretoforeconstructed 5 second, in an improved method of securing the stationarystone in the curb or case by the interposition of screwclamps betweenthe adjusting-screws in the curb and hoop of the stone, the hook-pointsof said clamps engaging with the hoop or the stone, with their screwends projecting through the back of the case, where they are providedwith proper nuts, by means of which the stone is held in tram, the wholebeing more particularly designed as an improvement on the grinding-millfor which Letters Patent were issued to me on the 3d day of November,1863.

In the drawings, A represents the runnerstone of my mill, having theiron hoop B shrunk on its periphery, but overhanging the back edge, asshown. C is a back plate or disk, having on its periphery a series ofprojections, a. O is the driving-pulley, andD the spindle, all of whichmay be cast in one piece or in separate parts, the whole being properlysecured together in any convenient manner. The disk 0 is laid againstthe back of the stone within the flange formed by the projecting edge ofthe hoop B. It will be noticed that theedges of the projections to aredepressed from their corners toward the -center on the outer face. Theback plate is secured to the stone by riveting or peening the hoop Binto the depressions formed in the. projections a.

The above-described method of securingthe parts together obviates alltendency to burst is the rear band or hoop shrunk on its periphery.

G are screw clamps or hooks projecting through the back'face of thecase, where they are provided with proper nuts G. The hook ends of theclamps engage with the edge of the hoop b. g

H are the tram-screws passing through the back of the case, and passingagainst the back of the stone.

I are the adjusting-screws, each of which passes through the peripheryof the'case and exerts its pressure on the back of the screwclamps G. I

The object I havein the employment of the hooks G is to hold thestationary stone in place back against the tram-screws, the setscrews Iserving to keep the hooks in engagement with the band of the stone, aswell as to prevent the stone from being moved out of place in the case.

The spaces between the projections a of the disk or back plate, 0, aredesigned to be used in balancing the stone by filling such of them withlead or other material as may be neces sary to accomplish that end. I donot intend, however, to confine myself to the use of these spaces forthat purpose, as the disk may be made solid and other methods ofbalancing employed.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. The arrangement of the runner-stone A, the hoop B, the back plate, 0,the projections a, the driving-pulley G, and the spindle D, whenconstructed as described and shown,

and as and for the purposes set forth.

2. The arrangement'of the stationary stone F, the case E, the edge b,the screw-clamps G, the nuts G, the tram-screws H, and the set-screws I,when constructed as described and shown, and as and for the purposes setforth. 7

JOSEPH A. FORSMAN...

Witnesses:

FREDERICK EBERTS, HARRY S. SPRAGUE.

